not been compromised. ukraine's president zelenskyy warns worse could still come. >> translator: there are 15 nuclear reactors in ukraine. in one of them blows, that's the end for everyone. that's the end of europe. all of europe will have to evacuate. immediate action must be taken to stop the russian army. don't allow the death of europe. stop this potential atomic catastrophe. >> president biden spoke to zelenskyy about the nuclear threat overnight. jennifer tpwgranholm tracking i. and an attack on an apartment building in chernihiv.